The present invention relates to an endoscopic photographing apparatus, and more particularly to an endoscopic photographing apparatus with an automatic exposure function.
In conventional endoscopic photographing apparatuses, automatic exposure photography is performed by calculating the output from a photosensitive element of the endoscope by means of an automatic exposure calculating circuit in a light supply unit, and terminating the emission of light from a light source in response to an output from the automatic exposure calculating circuit. However, such an automatic exposure photographing apparatus cannot calculate the exposure accurately, because of the response delay of the photosensitive element and the noise introduced by the long transmission line through which the output from the photosensitive element passes to the endoscope, etc. This tends to lead to incorrect exposure. To solve this problem, an automatic exposure calculating circuit is preferably provided in the camera. However, this will cause inconvenience to users, since it is impossible in this case to directly combine the camera having an automatic exposure calculating circuit with the light source unit having a similar circuit.